Not much is known about the life and times of Patanjali. Various references suggest he lived between 500 BC and 200 BC.
The Yoga Sutras probably date from around AD 200. They give us the earliest reference to the popular term Ashtanga Yoga which translates literally as the eight limbs of yoga. They are yama, niyama, asana, pranayama, pratyahara, dharana, dhyana and samadhi.